In that case the -daystart option may have been removed from find. I have to admit, I haven't used -daystart with find for a long time, I just know of it's existence (or former existence).
I'm at work ATM and not anywhere near a Linux terminal...
The -daystart option would set the start time for the search to the start of the day for the first day of the search.
So if it's 3pm and you are searching for files that were modified in the last 10 days without the -daystart option - then find would only include files from 10 days ago time-stamped from 3pm onwards. Whereas with the -daystart option, find would show files from the start of the day from 10 days ago onwards, so you were guaranteed to get ALL files from the first day.
Incidentally, the reason I've used a negative value (-10) with -ctime is to get ALL files that were created/modified in the last 10 days.
If I used a positive value (e.g. 10, or +10) with -ctime, it would only show files that were created EXACTLY 10 days ago.